The present invention relates to a regulator for the rotation direction of the rotor of a motor, and particularly a synchronous electric motor. The regulator uses a stopper that is controlled by cam means to regulate the rotation direction of the rotor.
A synchronous electric motor using a permanent magnet as its rotor is highly efficient. It, therefore, becomes possible to reduce the overall size of the electric motor, as compared with inductive electric motors. A synchronous electric motor has the additional advantage that there is scarcely any irregularity in the rotation of its permanent magnet rotor.
In "shaded" coil inductive electric motors the rotation direction of the motor rotor is automatically regulated. In contrast, one of the shortcomings of a synchronous electric motor is that the initial rotary direction of its rotor at start-up of the motor is not always predictable. This has led to the development of many different devices for regulating the rotary direction of a conventional synchronous electric motor rotor. Conventional solutions, however, make it quite difficult to significantly reduce the size of the synchronous motors, and the conventional regulating devices and/or the motors with which they are used have had quite short durability. In some prior synchronous motor rotary direction regulating devices, when the temperature of the coil of the motor becomes high in particular, it has been difficult to achieve rotary direction regulation due to the torque deficiency of the motor.